The subject matter disclosed herein relates to an engine installation and, more particularly, to an engine installation of a vertical take-off and landing (VTOL) aircraft.
Aircraft missions often require VTOL capability that is combined with long range and endurance and can be very demanding. Conventional configurations of such aircraft are designed primarily for efficient forward flight, for efficient vertical lift or a poor compromise solution that permits both forward and vertical flight. Alternatively, some configurations include tilt-wing or tilt-rotor features that allow tilting of the fuselage with respect to the nacelles and have VTOL capabilities, long range and endurance but pay a high penalty in terms of complexity, higher empty weight and other inefficiencies.
One particular configuration is a rotor blown wing (RBW) configuration where a hybrid aircraft can fly as a rotorcraft and as a fixed wing aircraft. This configuration places stringent requirements on the engine, however, and necessitates control of engine exhaust since engine exhaust can have adverse impacts if it is placed close to the trailing edge of the vehicle and the ground. Thus, RBW aircraft can use reverse or axial flow engines. Reverse flow engines offer good exhaust placement but limited selection and axial flow engines increase engine options but have less than desirable exhaust locations.